Let the volume of each container be V.
Initially, both containers are half-filled:
- First container: \( \frac{V}{2} \) sugar syrup
- Second container: \( \frac{V}{2} \) milk
Step 1: Transfer half the content from the first to the second container
- Sugar syrup transferred: \( \frac{V}{4} \)
- Now, second container has:
- Sugar syrup: \( \frac{V}{4} \)
- Milk: \( \frac{V}{2} \)
- Total in second container: \( \frac{3V}{4} \)
Step 2: Transfer half of this mixture back to the first container
- Mixture transferred: \( \frac{3V}{8} \)
- Proportions in the mixture:
- Sugar syrup part: \( \frac{V}{4} \)
- Milk part: \( \frac{V}{2} \)
- Sugar syrup transferred back: \( \frac{V}{4} \times \frac{1}{2} = \frac{V}{8} \)
- Milk transferred back: \( \frac{V}{2} \times \frac{1}{2} = \frac{V}{4} \)
Step 3: Transfer half of the first container back to the second
- Now in first container:
- Sugar syrup = remaining = \( \frac{V}{2} - \frac{V}{4} + \frac{V}{8} = \frac{5V}{8} \)
- Milk = \( \frac{V}{4} \)
- Total in first container = \( \frac{5V}{8} + \frac{V}{4} = \frac{7V}{8} \)
- Half transferred = \( \frac{7V}{16} \)
- Sugar syrup transferred = \( \frac{5V}{8} \times \frac{1}{2} = \frac{5V}{16} \)
- Milk transferred = \( \frac{V}{4} \times \frac{1}{2} = \frac{V}{8} \)
Final content in the second container:
- Existing sugar syrup = \( \frac{V}{4} \)
- New sugar syrup added = \( \frac{5V}{16} \)
- Total sugar syrup = \( \frac{9V}{16} \)
- Remaining milk in second container = \( \frac{V}{2} - \frac{V}{4} = \frac{V}{4} \)
- New milk added = \( \frac{V}{8} \)
- Total milk = \( \frac{5V}{16} \)
Final Ratio:
\[\text{Sugar Syrup : Milk} = \frac{9V}{16} : \frac{5V}{16} = \frac{9}{5}\]Final Answer: Ratio = \( \mathbf{9:5} \)